Propagation of the endangered Del Mar manzanita (Arctostaphylos glandulosa ssp. crassifolia) through tissue culture

The Del Mar manzanita (Arctostaphylos glandulosa ssp. crassifolia) is an endangered perennial shrub native to San Diego County, CA, USA. Although their seeds may be banked for years, germination rates are exceedingly low. Scarification, acid exposure, and heat shock require considerable time and effort to achieve improved germination rates. Tissue culture is a viable alternative. Del Mar manzanita nutlets were cracked with a mechanical vise to free the seeds, which were then surface sterilized and placed on a culture medium. After two weeks, 64.8% of the seeds germinated. All resulting plants were sectioned through shoot micropropagations to establish culture lines. Additionally, new cultures may be established by harvesting shoot tips and axillary buds from field trees, surface sterilizing them, and placing them on a culture medium. In this talk, I will cover my experiences in creating methods to conserve and propagate this iconic member of the Californian chaparral.